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Asian Journal of Healthy and Science
p-ISSN: 2980-4302
e-ISSN: 2980-4310
Vol. 3 No. 3 March 2024
EFFECT OF BOLUS THICKNESS-BASED BASE EICHHORNIA
CRASSIPES POWDER (WATER HYACINTH) ON RADIOTHERAPY
BOLUS HOMOGENEITY
Muslimah Putri Utami
1
, Sugiyanto
2
, Gatot Murti Wibowo
3
, Ari Suwondo
4
,
Yeti Kartikasari
5
, Mohamad Hidayatullah
6
1,2,3,4,5
Politeknik Kesehatan Kemenkes Semarang, Indonesia
6
Ken Saras Hospital Semarang, Indonesia
Email: mputriutami28@gmail.com
Abstract
Bolus radiotherapy aims to make the radiation dose more homogeneous, and
increase the surface dose to the skin. Exploration of alternative materials for
substitute mixtures that are relatively safer is needed to reduce the weaknesses in the
use of plasticine mixtures. To develop the basic ingredients for making bolus using
biopolymers in water hyacinth (Eichhornia crassipes). This research was conducted
using the method of Research and Development. The suitability of the physical
characteristics of the bolus (homogeneity judged by CT number; Relative Electron
Density is calculated by a formula ρb;% surface dose is obtained from TPS
(Treatment Planning System) in the test and the 3 variations of the thickness (0.5 cm,
1.0 cm and 1.5 cm). The feasibility of the bolus product was determined based on the
flexibility of the texture and resistance to cold temperatures. Result: Water hyacinth
(Eichhornia crassipes) can be used as a reference for alternative bolus materials in
radiotherapy due to the response of water hyacinth (Eichhornia crassipes) to
radiation Water hyacinth (Eichhornia crassipes-based bolus has same RED (Relative
Electron Density) value as soft and solid tissue in all thickness variations and has a
surface dose value of ±100% for all thickness variations. Water hyacinth (Eichhornia
crassipes) based bolus is homogeneous against radiation and can increase the dose
surface so that water hyacinth (Eichhornia crassipes) has benefits and can be used as
an alternative bolus material in radiotherapy.
Keywords: Bolus, Relative Electron Density, Eichhornia crassipes
INTRODUCTION
Radiotherapy or radiation therapy is a treatment for tumors using ionizing rays.
This type of ionizing rays can be in the form of x-rays and gamma rays, alpha and
beta, as well as from several groups of particles such as electrons and neutrons. One
of the radiotherapy modalities that is widely used is LINAC (Linear Accelerator)
(Dewang et al., 2015). The electron beam provides a uniform radiation dose within
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the target volume tumor (TV) superficial and can minimize radiation dose to deeper
tissues (Fairuzdzah et al., 2015). However, there are still obstacles to optimizing the
absorbed dose at the target volume to achieve homogeneity of the radiation dose
distribution because the influence of the irradiated surface contour varies (Jaya &
Sutanto, 2018). For example, in LINAC radiotherapy patients with breast tumors
post-mastectomy, the surface contour of the organ is not flat (flat) will affect the
distribution of the effective dose of surface irradiation on the TV (Kudchadker et al.,
2022; Ordonez-Sanz et al., 2014). As a result, there was an increase in the absorbed
dose precisely at locations deeper than the layer area where the superficial tumor was
located, which in turn reduced the effectiveness of dose distribution in the TV while
damage to healthy tissue in deeper locations occurred (Montaseri et al., 2012). To
overcome this problem, a radiotherapy facility known as a bolus is needed (Adamson
et al., 2017). The use of a bolus will provide a more homogeneous and higher dose to
the skin as optimization of treatment if without the use of a bolus it will cause damage
to the skin because 95% of the absorbed dose is on the skin and using a bolus dose of
the skin is <75% (Guhan et al., 2003; Kermode et al., 2005).
The main goal of bolus radiotherapy is to disguise the patient's irregular
contours and provide a flat surface for normal radiation (R.Oberoia et al., 2019).
Therefore, a bolus consists of a tissue-equivalent material that is placed directly on
the surface of the skin. The second bolus aims to treat lesions near the skin surface
which can be achieved by increasing the skin surface dose (Montaseri et al., 2012;
Khan and Gibbons, 2010; Khan, 2003)
The content of the bolus material must have components that have the
characteristics of homogeneously attenuating radiation beams, although the use of
natural base mixtures has been studied and applied, but the use of mixed materials
from the water hyacinth plant (Eichhornia crassipes) has not been studied in depth
(Cherry and Duxbury, 2019; Ordonez-Sanz et al., 2014). Water hyacinth (Eichhornia
crassipes) has high fiber content and low protein content, and water hyacinth
(Eichhornia crassipes) is a plant that contains high cellulose as a biopolymer so that it
has the potential to be used as a base for bolus mixtures because besides this plant
species it is easily available in nature (Heriyanto et al., 2015). Tropical geography
such as Indonesia, also meets the requirements for bolus radiotherapy (Fitasari, 2009;
IAEA, 2005; Sutanto et al., 2019).
For this reason, this research will conduct radiotherapy boluses based on water
hyacinth powder (Eichhornia crassipes) with bolus thicknesses of 0.5 cm, 1 cm and 1.5
cm. Water hyacinth powder is (Eichhornia crassipes) expected to be a new substrate in
the manufacture of radiotherapy boluses. The bolus will be analyzed using CT Scan
and LINAC to determine the value of Relative Electron Density (RED) and the
percentage of surface dose using 6 MV of energy (Wong et al., 2020). This study
aimed to was to develop the basic ingredients for making bolus using biopolymers in
water hyacinth (Eichhornia crassipes).
RESEARCH METHODS
The research method used is research and development (Research &
Development) which is a research method to produce certain products, and test the
effectiveness of these products. The development and research model used in this
study is the development model Borg and Gall which consists of ten implementation
steps including (1) research and information collecting, (2) planning, (3) develop
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preliminary form of product, (4) preliminary field testing, (5) main product revision,
(6) main field testing, (7) operational product revision, (8) operational field testing,
(9) final product revision, and (10) dissemination and implementation. To shorten
the time of research and development in this research is limited to a few stages. These
stages include: a) problems and potentials; b) product design; c) expert validation; d)
product trial; e) product feasibility test; f) preparation of reports (Margono, 2005;
Borg and Gall, 1983)
The population in this study is an infinite population because the researchers
used samples in the form of inanimate objects, namely radiotherapy boluses with
variations in thickness of 0.5 cm, 1 cm, and 1.5 cm. Meanwhile, the sample in this
study was a type of radiotherapy bolus made from Eichornia Crassipes, Water
Hyacinth Powder, and Plasticine Bolus given irradiation simulation using the same
energy 6 MV.
In this study, researchers collected data by explaining the procedures for
processing and analyzing data according to the approach taken. This study uses a
closed assessment questionnaire to provide criticism and suggestions as well as
product improvements. The results of this descriptive analysis are quantitative data
and qualitative data. Quantitative data is obtained from the calculation value using
the formula for determining the relative value of electron density and the percentage
of surface dose and the value of the validator, while the qualitative data is in the form
of a descriptive explanation of the research results and validation results
(Tampubolon et al., 2019; Metcalfe et al., 2007)
RESULT AND DISCUSSION
The results of the stages of product development for water hyacinth bolus
(Eichornia Crassipes) will be described as follows:
Problems and Potential
Research can begin with the emergence of problems with plasticine boluses,
namely boluses used today, made from paraffin or wax that do not last long in cold
temperatures and will harden if left for a while and the material used is not organic.
Therefore, the potential that can be raised is to make radiotherapy boluses made of
organic material by utilizing biopolymers in water hyacinth (Eichornnia Crassipes)
(Ratnani et al., 2011; Rorong and Suryanto, 2010).
Product design
This study used water hyacinth (Eichornnia Crassipes) as the base material for
radiotherapy bolus because it contains high cellulose, which is the main constituent
of plants composed of D-glucose subunits and is a linear biopolymer of
anhydroglucopyranose molecule (Zimmels et al., 2006). Tests were conducted on
water hyacinth (Eichornnia Crassipes) which had been powdered with a weight
variation of 5 gr ; 7.5 gr ; and 11 gr to determine the response to radiation. The test
was carried out using a CT-Scan to find out the CT Number value to calculate the
RED value and simulated irradiation on the linac at the TPS. The CT scan energy
used is 120 KV and 240 mA can be seen in the Table !below for the test results.
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Table 1. Value of CT Number and value of Relative Electron Density (RED)
water hyacinth
No
Water hyacinth
5.0 gr
7.5 gr
11.0 gr
1
-849.3
-880
-886
2
-854.5
-881.3
-878.9
3
-857
-879.1
-880.6
4
-858
-877.6
-878.6
Average
-854.7
-879.5
-881.026
RED
0.1453
0.1205
0.1189
In the Table 1 it can be explained that the RED value of water hyacinth powder
(Eichornnia Crassipes) is below the solid and soft tissues. However, water hyacinth
powder (Eichornnia Crassipes) has the opportunity to be used as a bolus in radiotherapy
because the fibers contained in water hyacinth powder (Eichornnia Crassipes) are able
to absorb radiation and spread radiation evenly. significant. Water hyacinth contains
organic polymer bonds in its cellulose, namely (C6H10O5).
Table 2. Radiation absorption dose of water hyacinth with energy 6 MV
Depth
Without bolus
5 gr
7,5 gr
11 gr
Surface
51.9
66.8
68.4
72.9
0,5 cm
89.4
91.1
91.2
92.3
1 cm
99.7
99.6
99.8
99.2
1,5 cm
100.6
99.8
99.8
99.1
2 cm
99.3
98.5
98.5
97.7
% surface dose
51.59%
66.40%
67.99%
72.46%
In Table 2, it can be concluded that water hyacinth (Eichornia crassipes) can
increase the surface dose as one of the bolus requirements. Water hyacinth (Eichornia
crassipes) can distribute radiation well seen from the value of the absorbed dose at
each depth.
The deficiency in water hyacinth (Eichornia crassipes) is due to the absence of
density which affects the density and reduces the RED value and the percentage of
surface dose. Gluten in wheat flour also has benefits as a viscoelastic bolus material
that is able to make the bolus more elastic and can be shaped according to the needs
of treatment in radiotherapy.
Several references, researchers determine olive oil as a lubricant because the
concentration of squalene in olive oil is higher than in other types of oil. Due to the
basic ingredients and mixed ingredients of water hyacinth bolus (Eichornia crassipes)
made of organic materials, an antifungal agent is needed in the form of Sodium
Tetraborate Decahydrate which is able to form complexes with various biomolecules
such as glucose, protein and fat contained in wheat flour and water hyacinth powder
(Eichornia crassipes) (Damat et al., 2020)
The right composition for variations in the thickness of 0.5 cm, 1 cm and 1.5
cm is (42:10:2:2) tbsp. Due to the different density of wheat flour and water hyacinth
powder, it cannot be measured using a weighing scale. The process of making water
hyacinth bolus (Eichornia Crassipes) sodium tetraborate decahydrate must be dissolved
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first, and burned using distilled water or water at a rate of 0.2 gr: 100 ml, and stirred
until dissolved. Water hyacinth powder, wheat flour, olive oil and a solution of
sodium tetraborate decahydrate were placed in a bowl that had been prepared with
the dose that the researchers had managed to get, namely 42 tbs. water hyacinth
powder 10 tbsp wheat flour 2 tbsp olive oil 2 tbs solution sodium tetraborate
decahydrate. From this dose, 3 types of water hyacinth bolus can be made with
variations in thickness of 0.5 cm, 1 cm, and 1.5 cm. After the dough is mixed and
gets the right texture, the bolus can be in the form of a square with a field area
commonly used for boluses, which is 10x10 cm. If you want to make boluses one at
a time, the required dose is 14 tbs of water hyacinth powder, 2 tbs of wheat flour, 1.5
tbs of olive oil and 1.5 tbs of solution sodium tetraborate decahydrate apply in
multiples of 2 to make a bolus of the desired thickness.
Validation
Validation (Table 3 and Table 4) was carried out by distributing an assessment
questionnaire on the water hyacinthbolus (Eichornia crassipes). carried out by: 1) a
competent material expert in the field of radiotherapy physics; and 2) a competent
radiotherapist.
Table 3. Validation of water hyacinthbasic ingredients (Eichornia crassipes) by
material expert who is competent in the field of radiotherapy physics
No
Description
Water Hyacinth
Validation
1
2
3
4
1
Water hyacinth bolus characteristics
v
2
Homogeneity to radiation
v
3
Bolus response to radiation with variations in
thickness
v
4
Percentage of surface dose
v
5
Development of organic bolus
v
6
Effectiveness cost of manufacture
v
7
Effectiveness of making bolus
8
Availability of bolus material
v
Table 4. Validation of water hyacinthbase material (Eichornia crassipes) by
competent radiotherapist
No
Description
Validation
1
2
3
4
1
Water hyacinth bolus characteristics
v
2
Homogeneity to radiation
v
3
Bolus response to radiation with variations in
thickness
v
4
Percentage of surface dose
v
5
Development of organic bolus
v
6
Effectiveness cost of manufacture
v
7
Effectiveness of making bolus
v
8
Availability of bolus material
v
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Based on the validation results, it can be concluded that water hyacinth
(Eichornia crassipes) can be used as the basis for making a good radiotherapy bolus.
This can be proven by the score on the validation questionnaire.
Table 5. Water hyacinth bolus validation (Eichornia crassipes) by material expert
who is competent in radiotherapy physics
No
Description
Mixed EG Bolus
Validation
1
2
3
4
1
Characteristics of bolus to tissue
v
2
Homogeneity to bolus
v
3
Response to radiation with variations in
thickness
v
4
Percentage of surface dose on bolus
v
5
Development of organic bolus
v
6
Effectiveness cost of manufacture
v
7
Effectiveness of making bolus
v
8
Availability of bolus material
v
The results of product validation (Table 5) by a competent material expert in
the field of radiotherapy physics show the results of scores of 3 and 4 with a
percentage >50% for all questions in the “good” and “very good".
Table 6. Water hyacinth bolus validation (Eichornia crassipes) radiotherapist
No
Description
Validation
1
2
3
4
1
Characteristics of bolus to tissue
v
2
Homogeneity to bolus
v
3
Response to radiation with variations in thickness
v
4
Percentage of surface dose on bolus
v
5
Development of organic bolus
v
6
Effectiveness cost of manufacture
v
7
Effectiveness of making bolus
v
8
Availability of bolus material
v
The results of product validation (Table 6) by a competent radiotherapist
showed an overall score of 4 with a percentage of 100% in the "very good" category.
For product characteristics, it shows a value of 3 with a percentage of 75% in the
"good" category.
Product
Trial the trial was carried out at Ken Saras Hospital, Semarang. Variations in
bolus thickness of water hyacinth (Eichornia crassipes) 0.5 cm, 1 cm and 1.5 cm with
an energy of 120 kV 240 mA on CT Scan, energy 6 MV on LINAC. To determine
the effectiveness of a water hyacinth bolus compared to a routine bolus, namely a
plasticine bolus. Then the plasticine bolus was measured and compared with the
water hyacinthbolus (Eichornia crassipes).
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Table 7. CT Number Value and Relative Electron Density (RED) Water
Hyacinth Bolus and Plasticine Bolus
No
Water hyacinth Bolus
Plasticine Bolus
0.5 gr
1.0 gr
1.5 gr
0.5 gr
1.0 gr
1.5 gr
1
64.8
77.6
82.1
95.8
112.8
119.8
2
67.6
74.9
66.1
107.6
97.5
118.7
3
75.6
77.8
73.3
100.1
102
118.7
4
71.1
63.8
66.6
109.5
99.6
112.2
Average value
69.775
73.525
72.025
103.25
102.975
117.35
RED
1.0854
1.0872
1.0865
1.1015
1.1014
1.1083
Table 7 explains that the water hyacinth bolus has a value equivalent to soft
tissue (muscle and breast) and solid tissue (solid bone) and has a RED value that is
almost the same as a routine bolus, namely a plasticine bolus.
Table 8. Radiation Absorption Dose Value of 6 MV on Water Hyacinth Bolus
and Plasticine Bolus
n
Without
Water hyacinth Bolus
Plasticine Bolus
0.5 gr
1.0 gr
1.5 gr
0.5 gr
1.0 gr
1.5 gr
Surface
51.9
98.8
101
101.7
98.5
100.7
101.3
0.5 cm
89.4
100.5
102.1
100.2
101.7
100.3
98
1 cm
99.7
99.7
100.7
98.1
101.6
98.9
96.8
1.5 cm
100.6
97.7
98.6
95.7
99.1
96.9
94.4
2 cm
99.3
95.6
96.3
93.4
97
94.3
92
% surface dose
52.26%
99.49%
101.71%
102.41%
99.19%
101%
102%
In Table 8 it can be explained that the higher the radiation energy used, the
percentage of surface dose without the use of a bolus the increase is due to the
difference in scattering (scattering) that occurs when the radiation particles pass
through the medium (solid phantom) (Montaseri et al., 2012). Water hyacinth bolus
(Eichornia crassipes) has a higher percentage of surface dose compared to routine bolus,
namely plasticine bolus because water hyacinth powder (Eichornia crassipes) and
wheat flour have elastic and non-elastic collisions which cause the release of
secondary electrons as a result of the ionization process, so that These secondary
electrons can penetrate deeper into the position of maximum dose depth (Dmax).
Product feasibility test
The feasibility test is carried out by looking at the results of product validation
and by looking at the bolus with the naked eye the results of the bolus s can be seen
in Figure 1.
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Figure 1 Plasticine bolus, water hyacinth powder, water hyacinth powder ((a)
0.5 cm plasticine bolus, (b) 1 cm plasticine bolus, (c) 1.5 cm plasticine bolus, (d )
water hyacinth powder 5 gr, (e) water hyacinth powder 7.5 gr, (f) water hyacinth
powder 11 gr, (g) water hyacinth bolus 0.5 cm, (h) water hyacinth bolus 1 cm, (i)
water hyacinth bolus 1.5 cm)
In Figure 1 it can be seen the color difference of each bolus according to the
color of the basic ingredients used. Water hyacinth boluses (Eichhornia crassipes) have
a more elastic texture than plasticine boluses so that water hyacinth boluses
(Eichhornia crassipes) can be more easily shaped according to needs in both cold and
normal temperatures. And the elasticity level of the water hyacinth bolus is better
when compared to the plasticine bolus which will harden at a certain time and have
an influence on the radiation dose that will be transmitted to the target. Thus, it can
be concluded that the water hyacinth bolus (Eichhornia crassipes) has advantages for
users in terms of texture and bolus resistance.
This research and development was carried out with reference to the research
and development stages of Borg & Gall which explained that there were ten stages in
research and development, but in this study the ten steps were simplified into six
steps. The factors that underlie the simplification are: time constraints, limited costs,
similarity in stages, and opinions according to Borg & Gall.
The bolus characteristics of water hyacinth (Eichhornia crassipes) can be seen
from the Relative Electron Density (RED) value and the percentage of surface dose.
It can be seen from Table 1 and Table 2 which states that the water hyacinth bolus
(Eichhornia crassipes) has the same RED value as the routine bolus, namely the
plasticine bolus and has a higher surface dose percentage value than the plasticine
routine bolus. Therefore, it can be concluded that the water hyacinth bolus
(Eichhornia crassipes) has the potential to be used as an organic- based radiotherapy
bolus.